Medical devices to be inserted in vivo, such as catheters, guidewires, indwelling needles and the like, are required to have excellent lubricity in order to reduce tissue damage in blood vessels or the like and also improve the operability for the operator. For this reason, methods for forming a coating of a hydrophilic polymer having lubricity on the surface of a base layer have been developed and put into practical use. In such a medical device, the elution/peeling of the hydrophilic polymer from the base layer surface is problematic in terms of maintaining the safety and operability. For this reason, a coating of a hydrophilic polymer is required to have not only excellent lubricity but also durability against loads such as abrasion, scratching and the like.
From such a point of view, PTL 1 discloses a medical device, which is obtained by dissolving a water-soluble or water-swellable polymer in a solvent that swells a base layer of a medical device to produce a polymer solution, immersing a base layer of a medical device in the polymer solution to cause swelling, and further crosslinking or polymerizing the polymer on the base layer surface, thereby forming a surface lubricating layer on the base layer surface.
According to the technique disclosed in PTL 1, a surface lubricating layer having relatively excellent lubricity can be fixed to a base layer.
PTL 1: JP-A-8-33704 (corresponding to U.S. Pat. No. 5,670,558)